Vacuum cleaner filter bag

ABSTRACT

A vacuum cleaner bag is made from a blank sheet of air permeable material which defines a front wall, a rear and a pair of opposing side walls. Opposing edges of the blank are secured together in an overlapping relation to define a tube-like member. The walls are joined at one end of the bag to define a portion having a narrow cross-section. The front and rear walls diverge from each other in a direction away from the one end when the bag is expanded. A top wall is connected to the other walls at the other end of the bag. Fold lines are provided in the walls to permit movement of the bag from a collapsed condition, wherein the top and rear walls face a common direction opposite to the direction in which the front wall faces and wherein at least a portion of the front wall is in opposition and adjacent to a portion of the top wall, to an expanded condition, wherein the top wall is substantially normal to the longitudinal length direction of the bag. Access means in the form of a reenforced aperture adapted to cooperate with a vacuum cleaner element is provided in the front wall portion facing the top wall portion in the collapsed condition of the bag for providing access to the interior of the bag. In this manner, air directed through the aperture impinges on the top wall portion and urges the separation between the front and rear walls to cause the bag to move to an expanded condition suitable for receiving waste material.

United States Patent 1191 Fesco Sept. 23, 1975 Primary Examiner-Bernard Nozick Attorney, Agent, or FirmFriedman & Goodman ABSTRACT A vacuum cleaner bag is made from a blank sheet of air permeable material which defines a front wall, a

rear and a pair of opposing side walls. Opposing edges of the blank are secured together in an overlapping relation to define a tube-like member. The walls are joined at one end olthe bag to define a portion having a narrow crosssection. The front and rear walls diverge from each other in a direction away from the one end when the bag is expanded. A top wall is connected to the other walls at the other end of the bag. Fold lines are provided in the walls to permit move ment of the bag from a collapsed condition. wherein the top and rear walls face a common direction opposite to the direction in which the front wall faces and wherein at least a portion of the front wall is in oppo sition and adjacent to a portion of the top wall. to an expanded condition. wherein the top wall is substan tially normal to the longitudinal length direction of the bag. Access means in the form of a reenforeed aper' ture adapted to cooperate with a vacuum cleaner element is provided in the front wall portion Facing the top wall portion in the collapsed condition of the bag for providing access to the interior of the bag. In this manner, air directed through the aperture impinges on the top wall portion and urges the separation between the front and rear walls to cause the bag to move to an expanded condition suitable for receiving waste mate rial.

3 Claims, 9 Drawing Figures US Patent Sept. 23,1975 Sheet 1 of2 3,907,530

US Patent Sept. 23,1975 Sheet 2 of2 3,907,530

FIG.T

FIG.6

VACUUM CLEANER FILTER BAG BACKGROUND OF THE INVENTION This invention generally relates to disposable type filtcr bags for use with vacuum cleaning devices, and mar. particularly to a filter bag which expands from a folded condition in more reliable fashion and which may be utilized to project an incoming air stream and waste material into the bag against reenforced portions thereof to prevent breakage of the bag. This is accomplished by appropriate location of the access opening in a longitudinal side of the bag instead of conventionally locating the same at the end walls thereof.

Vacuum cleaner paper bags of various types are al ready known. Numerous problems, however, are assoelated in the construction, manufacture and use of these bags Where it is desired to make paper bags of increased capacity and special shapes adapted to differ ent shape vacuum cleaning devices, different machines have to be set up to take care of different bag sizes and shapes. One problem has been the provision of access means through a bag bottom wall or end wall which provides access to the interior of the bag. Generally, what is done is to provide a centrally located aperture in the bag bottom to which is attached a mounting collar with the other end of the bag being closed. The problem with this is that in order to provide the apcr' titre. several layers of the bag bottom have to be cut through or multiple holes have to be provided in the bag blank, this resulting in a relatively complicated bag construction. A vacuum cleaner filter bag which overcomes this problem is dcscribcd in my US. Patv No. 3,6l6,62l. By placing the access means off'ccnter, as described in the patent. a simplified bag construction is made possible.

In use. filter bags are generally attached to a vacuum cleaner clement while the bag is still in a folded condition. This generally entails the passage of a tubular member through an aperture in the filter bag. Because many filter bags are mounted in this folded condition, it is important that the filter bag expand sufficiently during use to assure that the maximum capacity of the bag is achieved for receiving the waste material. However, many of the filter bags, because of their construction, do not fully expand as desired and, consequently, the bag provides indications of being full before its full capacity has been reached. in effect, these bags, which are designed and constructed for higher capacities, are equivalent to lower capacity bags because of their failure to fully expand from the folded condition.

In the use of a vacuum cleaner bag, as it is known to those skilled in the art, a rapid stream of air is directed through an aperture or opening in a wall of the bag, the stream of air carrying the dust and waste materials which the vacuum cleaner is to collect. Since the stream of air generally impinges on an interior surface of the bag, it is important that that surface be sufficiently strong to withstand the recurrent blasts of air which are directed at it. A disadvantage of many ofthe prior art vacuum cleaner bags is that the bags are not sufficiently reenforccd. particularly when moisture or water droplets are included in the stream of air. Accordingly, the surface which is exposed to the stream weakens with extended use and, in some cases, breaks. This poses a problem to the user since the dirt which has been collected within the bag is expelled into the vacuum cleaner structure and, possibly, into the surroundings being cleaned.

SUMMARY OI THE INVENTION Accordingly, it is an object of the present invention to provide a vacuum cleaner filter bag which does not have the above described disadvantages associated with prior art filter bags.

It is another object of the present invention to provide a vacuum cleaner filter bag which is simple in construction and economical to manufacture.

It is still another object of the present invention to provide a filter bag of the type under discussion which locates the access means through which the waste materials enter the bag in a longitudinal wall of the bag and not at the end walls thereof as in conventional bags.

It is yet another object of the present invention to provide a vacuum cleaner lilter bag as above described which fully expands from a folded condition during use of the bag It is a further object of the present invention to provide access means or an inlet opening in a vacuum cleaner bag as contemplated above which is disposed adjaccntly to a multi-Iaycred reenforced wall which is adapted to withstand the jets of air impinging thereon to thereby increase the life of the filter bag and prevent breakage thereof.

In order to achieve the above objects. as well as others which will become apparent hereafter, a vacuum cleaner filter bag in accordance with the present invcw tion comprises a blank sheet of air permeable material defining a front wall, a rear wall and a pair of opposing side walls. Opposing edges of the blank are secured together in an overlapping relation to define a tube-like member. The walls are joined at one end of the bag to define a closed portion having a narrow cross section. Said front and rear walls diverge from each other in a direction away from said one end when the bag is in a fully expanded condition. A top wall is connected to said other walls and is substantially normal to the longitudinal length direction of the bag when the latter is in a fully expanded condition. Access means are provided in said front wall proximate to said top wall for provid ing access to the interior of the bag.

In the presently preferred embodiment, said top and rear walls face a common direction opposite to the di rcction in which said front wall faces when the bag is folded, at least a portion of said front wall being in opposition and adjacent to a portion of said top wall. In the expanded condition said top wall is substantially normal to the longitudinal length direction of the bag. With such an arrangement. said access means is advantageously provided in said front wall portion facing said top wall portion in the collapsed or folded condition of the bag. In this manner, air directed through said access means impinges on said top wall portion and urges the separation between said front and rear walls to cause the bag to move to an expanded condition suitable for receiving waste material.

A blank foldable into a vacuum cleaner filter bag in accordance with the present invention comprises a sheet of air permeable material substantially rectangular in configuration. A first transverse fold line is pro vided adjacent to one transverse marginal edge of said sheet. A second transverse fold line is spaced between said first transverse fold line and said one transverse marginal edge. A plurality of longitudinal fold lines are spaced between the longitudinal marginal edges of said sheet and intersect said first and second transverse fold lines to define a front wall fonning member, a rear wall forming member and a pair of opposing side wall forming members. Pairs of slits are provided in said top wall forming member which longitudinally extends from said one transverse marginal edge. Diagonal fold lines extend from said slits to intersection points within said side wall forming members, said intersection points each being located at said first transverse fold line and a longitudinal fold line extending along the center of a corresponding side wall forming member. Said slits and said diagonal fold lines allow the top wall, when assembled, to move from a folded position substantially parallel to the front and rear walls of the resulting bag to a position substantially normal to the longitudinal direction of the bag when the same is in an expanded condition. Aperture means are provided in a portion of said front wall forming member which is positionable in opposition to said top wall forming member when the bag is assembled and in a folded condition.

The blank and vacuum cleaner bag construction in accordance with the present invention overcomes the above described disadvantages inherent in many prior art bags. Firstly, by locating the access means in a front wall or longitudinal surface of the bag, as opposed to the prior art end wall locations of the bag, the incoming stream of air forces the separation between the greater surface longitudinal walls to assure a fully expanded condition of the bag during use. Further, the resulting construction provides a top wall which is multi-layercd, and, consequently, reenforced. By locating the access means or the aperture in the bag adjacently to the top wall and by directing the stream of air at this wall, the top wall represents a reenforced surface which can withstand the recurrent bursts of high velocity, air and waste particles without damage or breaking.

BRIEF DESCRIPTION OF THE DRAWINGS With the above and additional objects and advan tages in view, as will hereinafter appear, this invention comprises the devices, combinations and arrangements of parts hereinafter described and illustrated in the accompanying drawings of a preferred embodiment in which:

FIG. 1 is a front elcvational view of a bag in accor dance with the present invention, shown in a substantially folded condition and showing the location of the access means or aperture in the bag disposed adjacently to the upper end of the bag. as viewed in this FIGURE;

FIG. 2 is a cross section of the bag shown in FIG. 1, taken along line 22;

FIG. 3 is a rear elevational view of the bag shown in FIGS. 1 and 2, showing the manner in which the top wall of the bag is substantially coextensive with the rear wall when the bag is folded;

FIG. 4 is a top plan view of a blank utilized in the construction of the bag shown in FIGS. 1-3, showing the slits and the fold lines which are provided in said blank to facilitate assembly of the bag;

FIG. 5 is a cross section of the bag shown in FIG. 3, taken along 5-5;

FIGS. 6 and 7 are partially fragmented side elevational views of the bag shown in FIGS. 13, showing the manner in which the location of the aperture on the filter bag proximate to the top wall thereof causes the filter bag to expand from a folded condition during the use of the bag; and

FIGS. 8 and 9 are similar to FIGS. 6 and 7, but wherein a stream of air is directed in an upward direction to impinge upon the top wall of the filter bag which is formed of multiple layers and is thereby reenforced to withstand the streams of air and particles impinging thereon.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now specifically to the drawings, wherein the identical or similar parts have been designated by the same reference numerals throughout, and first referring to FIGS. 13, a vacuum cleaner bag in accordance with the present invention is generally designated by the reference numeral 10.

The bag 10 defines a front wall 12, a rear wall 14 and a pair of opposing side walls 16. Connected to the aforementioned walls at one end of the bag 10 is a top wall 18. At the other end of the bag 10, the walls 12, I4 and 16 are joined at a closed end 20. In the preferred embodiment, the closed end is formed by rolling the aforementioned walls several turns, as best shown in FIG. 2, and maintained in this condition by any conventional manner such as by the use of adhesive.

Generally described, the bag 10 has a substantially triangular cross section when cut at a longitudinal plane disposed normally to the front and rear walls 12, I4 and when the bag is in an expanded condition, as suggested in FIGS. 7 and 9. The specific construction of the bag will be described hereafter in connection with FIGS. 1-5.

An important feature of the present invention is the provision of access means or aperture means, generally designated by the reference numeral 21, in the front wall 12 proximate to the point where the latter is joined to the top wall 18. The advantages of this specific construction will be described hereafter in connection with FIGS. 6-9.

The access or aperture means 21 comprises an opening in the front wall, which may be in the form of a removed section from the wall or may consist of a flap punched out in the wall. An apertured securing means in the form of a mounting collar 24 is provided and disposed coextensively with the opening or aperture in the bag. The mounting or retaining collar may comprise a stiffening member in the form of a cardboard member. An aperture 22 in the mounting collar is aligned with the aperture in the wall. The mounting collar may be joined to the front wall 12 in any conventional manner, such as by adhesive.

Joined to the mounting collar 24 is a resilient member 26 which has an aperture 28 smaller in size than the aperture 22 provided in the mounting collar and in the aperture in the front wall 12. The aperture 28 is aligned with the two aforementioned openings. In this manner, the passage of a vacuum cleaner element having the larger dimensions of the aperture 22 in the mounting collar causes the element to be frictionally engaged by the resilient member or sheet to prevent inadvertent separation between the element and the bag during use. For this purpose, the resilient member 26 may comprise a thin sheet of elastomerie plastic material or rubber sheeting.

The references in this application to directions, i.e., front, rear, side and top, are only for reference purposes for facilitating the description of the invention. These directions have no particular significance with respect to the basic principle of the invention which is herein sought to be protected.

The access means 21 is shown disposed in the upper, left-hand corner, as viewed in FIG. 1. The reason for disposing the access means 21 in the upper region of the bag as viewed in the FIGURES, adjacently to the top wall 18, will be described hereafter. However, the specific location of the access means 21 along the width of the front wall 12 is not a critical feature of the present invention. Thus, the access means may be provided in the upper, right-hand corner of the front wall 12 or at an intermediate position. This is, clearly, dictated by the design of the vacuum cleaner in which the bag is to be used. Here, the reasons for positioning the access means 21 off-center is not based on the same considerations as those disclosed in my US. Pat. No. 3,6l6,62 1, wherein the access means was provided at an end wall of the bag as opposed to a longitudinal side wall. However, the object of that patent in reducing the number of apertures which need be provided in the blank for simplifying the assembly and the machinery which assembles these bags is similarly accomplished by the present construction. In fact, only one aperture need be provided in the blank which forms the present filter bag, as to be described in connection with FIG. 4. In this respect, the filter bag is extremely simple to construct, since it is not necessary to align a plurality of apertures in a blank which, when the bag is assembled, together define an opening therein. For this reason, the

assembly of the subject bag is less critical and the equipment which forms the same may be less complex in construction and operation.

Referring to FIG, 4, a blank 29 is shown which, when assembled. forms the bag 10 described above. The basic blank 29, with the exception of the location of the aperture or access means opening, is substantially the same as that shown and described in my U.S. Pat. No. 3,616,621 The assembly procedures of the two bags is essentially the same and, to the extent to which the procedure are not described in this application, reference is hereby had to my above referenced patent for a more detailed and fuller description of the procedure or steps in the assembly of the bag from the blank.

The blank 29 is generally rectangular in configuration and is defined by two transverse marginal edges 30 and 32 which determine the length of the bag. Spaced from the marginal edge 30 is a transverse fold line 34 which is parallel to the marginal edge 30. Disposed between the transverse marginal edge 30 and the fold line 34 is a second transverse fold line 36 which is parallel to the aforementioned fold line and the marginal edge.

The blank 29 is also defined by generally shorter longitudinal marginal edges 38 and 40. A plurality of Iongitudinal fold lines 4247 are provided which are spaced between the longitudinal marginal edges 38 and 40 as shown in FIG. 4 and these longitudinal fold lines intersect the transverse fold lines 34 and 36 to define a series of panels which, singly or in combination, detinc a front wall forming member, a rear wall forming member, a pair of opposing side wall forming members and a top wall forming member. These latter wall form ing members respectfully form the front, rear, side and top walls above described in connection with FIGS. 1-3 when the blank 29 is assembled into the bag 10.

A pair of slits 48 and 49 are provided in the region of the longitudinal marginal edge 38 and a similar pair of slit 50 and 51 are provided in the region of the longitudinal edge 40. Each of the slits 48-51 are parallel to each other and to the longitudinal fold lines and marginal edges and extend longitudinally from the transverse marginal edge 30 towards the transverse fold line 36. The slits 48 and 50 are disposed to the left of longi tudinal fold lines 42 and 45 respectively while the slits 49 and 51 are disposed to the right of the respective longitudinal fold lines 44 and 47, as viewed in FIG. 4.

Diagonal fold lines 54 and 55 extend from the slits 48 and 49 respectively to an intersection point 56 within a side wall forming member 16. The intersection point 56 is located at the transverse fold line 34 where the latter intersects the longitudinal fold line 43 which extends along the center of the corresponding side wall forming member. Similarly, the diagonal fold lines 58 and 59 extend from the slits 50 and 51 to an intersection point 60 at a point where the transverse fold line 34 intersects the longitudinal fold line 46 extending along the center of the other side wall forming member.

The aforementioned slits and fold lines permit the top wall 18, when assembled, to move from a folded position substantially parallel to the front and rear walls 12, 14 of the resulting bag 10 to a position substantially normal to the longitudinal direction of the bag 10 when the same is in an expanded condition.

The above described fold lines and slits divide the blank 29 into a plurality of panels. The longitudinal fold lines 4247 divide the blank 29 into seven longitudinal sections A-(l. The slit 48 and the diagonal fold line 54, together with the transverse fold line 34 and 36 divide the section A into panels A1A4. The transverse fold lines 34 and 36, together with the diagonal fold line 54 divide the section B into panels Bl-B4. Similarly, the section C is divided into panels C1-C4 by the transverse fold lines 34 and 36 and the diagonal fold line 55. The diagonal fold lines 34 and 36, the diagonal fold lines 55 and 58, and the slits 49 and 50 divide the section D into panels Dl-DS. Sections E, F and G are divided respectively into panels til-E4, F1-F4, and G1G4 similarly to the manner in which sections C, B and A are divided. The division of the sections E, F and G is accomplished by means of the transverse fold lines 34 and 36, diagonal fold lines 58 and 59 and the slit 51.

An important fold line portion is defined by the reference numeral 62, this fold line portion being that portion of the transverse fold line 36 which extends between the longitudinal fold lines 44 and 45. The fold line portion 62 is, as will become apparent hereafter, the fold line which separates the front wall 12 from the top wall 18 when the bag 10 is fully assembled. This fold line portion 62 is indicated in FIGS. 2 and 69.

An important feature of the present invention is the provision of access means in the front wall 12, as described above, adjacent to the top wall 18. To locate the access means 21 in the position described above, an opening or aperture is provided between the fold line portion 62 and the fold line 34. The aperture may eonsist of a section removed from the panel D4, or, as shown, may consist of a flap 64 punched out in the panel D4. As described above, the flap 64 may be disposed anywhere within the panel D4 between the longitudinal fold lines 44 and 45 and the transverse fold line 34 and transverse fold line portion 62. The construction of the reenforcing member which retains the bag connected to a vacuum cleaner element is not critical insofar as the present invention is concerned and any reenforcing or stiffening arrangements may be utilized. For example, the access means 21 described in connection with HO, 1 or the rectangular collar described in my above referenced issued patent are suitable for this purpose.

The blank 29 may be formed of any suitable sheet of air permeable material commonly used in the manufac turcr of vacuum cleaner filter bags. Advantageously, the bag is chemically treated to inhibit the growth of bacteria, resist mold and mildew and retard growth of fungi. The tabs 66 and the cutouts 68 are formed in the manufacture of blanks with certain machinery. However, these blanks and cutouts are not essential features of the present invention and may be deleted without compromising the advantageous features of the present invention.

The assembly of the bag from the blank 29 will now be described. The blanks A4, B4 and C4 are folded about respective fold lines 42, 43 and 44 and the panels E4, F4 and G4 are similarly folded about respective fold lines 45, 46 and 47 to bring the panels B4 and C4 into opposition to one another and bring the panels E4 and F4 into opposition to each other as shown in FIG. 5. When this is done, the panels A4 and G4 overlap at the longitudinal marginal edges 38 and 40 as shown in FlG. 5 to together define the rear wall 14. The marginal edges are now joined together as with adhesive. The rear wall 14 is thereby positioned in opposition to the panel D5 which forms the front wall 12.

The panels A2, B1, C1 and D2 are then folded about the fold lines 36, 54 and 55 to bring the panels C2 and C3 into opposition with one another and to bring the panels B2 and B3 into opposition to one another. Similarly, the panels D3, El, F1 and G2 are folded about the fold lines 36, 58 and 59 to bring the panels E2 in opposition to the panel E3 and to bring the panel F2 in opposition with the panel F3. When this is achieved, the panels B2, B3, B4, C2, C3, C4 form one side wall 16 while the opposing side wall 16 is formed by the panels E2, E3, E4, F2, F3, and F4. Each of these side walls 16 is in the form of a gusset which can be folded or collapsed as suggested in FIGS. 2 and 69.

The panels A1, A2, G1 and G2 are now folded about the fold lines 36, 42 and 47 to bring the panels A1, A2, G1 and G2 into overlapping relationship with the panels Bl and F1. Similarly, the panels D1, D2 and D3 are folded about fold lines 36, 44 and 45 into abutting relationship with respective panels C1 and El. When this is done, the panel D1 is moved into overlapping rela tionship with the panels B1, C1, E1, F1 and at least partially abuts against panels A1 and G1.

The panels A4 and G4 are initially joined to each other at the edges 38 and 40 in any conventional manner, such as by adhesive. Adhesive is now provided between the panels Cl and D2, A2 and B1, D3 and E1, G2 and F1, as well as between D1 and each of the panels A1 and G1. In this construction, it becomes clear that the top wall 18 comprises a multi-layered arrangement which includes panels A1, G1, A2, G2, B1, F1, Cl, E1, D2, D3, and D1. This multi-layered top wall is used to advantage in the present construction to withstand the streams of air and particles which flow into the bag, as will be described hereafter.

The final step in assembly of the bag is the rolling up of the panels A4, B4, C4, D5, E4, F4 and G4 or the front, rear and side walls to form the closed end 20. As described above, any suitable conventional means may be utilized to retain the rolled condition of the end of the bag.

The advantages of the present vacuum cleaner filter bag 10 over the known prior art bags will be described in connection with FIGS. 69. By locating the inlet means 21 in the front wall 12 proximate to the top wall 18 or adjacent to the fold line portion 62, the inlet means 21 is disposed on a portion of the front wall 12 which is in opposition to a portion of the top wall 18 when the bag is folded. Referring to FIGS. 6 and 7, a tubular vacuum cleaner element is shown to be connected to, in cooperating relationship, with the inlet means 21. The arrow 72 represents a stream of air which contains the particles of waste material, and possible moisture in the form of liquid droplets. The fragmented view illustrates that the jet or stream of air 72 impinges upon the top wall 18 which causes the latter to angularly move or pivot about the fold line portion 62, moving towards a position substantially normal to the front wall 12. When this is done, the top wall 18 unfolds the rear wall 14 to thereby unfold the bag to a substantially fully extended condition as shown in FIG. 7. When the top wall 18 has moved sufficiently to move out of the stream 72, the rear wall 14 now intercepts the stream and the latter causes the front and rear walls 12 and 14 to separate, this further causing the bag 10 to move to the extended condition, Thus, a first important feature of the present invention is the specific location of the inlet means 21 as above described to utilize the jet or stream of air which is introduced into the bag to expand the bag during use of the same.

When the vacuum cleaner tubular element 70 is disposed as shown in FIGS. 6 and 7, the portion of the rear wall 17 in opposition to the opening 21, designated by the reference numeral 74, may be reenforced in any conventional manner to withstand the recurrent stream of air, waste particles and, possibly, humidity which impinges thereon during use of the bag.

To avoid the reenforcement of the portion 74 as above described, it is possible, with the improved bag of the present invention, to orient a vacuum cleaner element 70' in a direction which causes the stream of air 72' to be more upwardly directed than the stream 70, as viewed in the FIGURES. With such positioning of the vacuum cleaner element 70', the stream of air 72' impinges initially on the top wall 18 to open the bag, as described above, and continues to impinge upon the multi-layercd and recnforced top wall 18 during use, as suggested in FIG. 9. With this arrangement, no additional reenforcement is necessary since the top wall 18 is sufficiently reenforced to withstand the eroding forces generated by the stream 72'. Herein lies a sec ond important feature of the present invention. As just described, positioning of the access means 21 in the front wall 12 adjacent to the generally stronger, multilayered top wall 18 permits continued interception of the same of the erosive air stream 72'. impingement of the air stream on the top wall 18 increases the life span of the bag 10 and prevents breakage of the same.

Numerous alterations of the structure herein disclosed will suggest themselves to those skilled in the art. However, it is to be understood that the present disclosure relates to a preferred embodiment of the invention which is for purposes of illustration only and is not to be construed as a limitation of the invention.

I claim:

1. A vacuum cleaner filter bag comprising a blank sheet of air permeable material defining a front wall, a rear wall of substantially the same width as the front wall and a pair of opposing side walls, opposing edges of said blank being secured together in an overlapping relation to define a tube-like member, said opposing edges of said blank defining cooperating portions of said rear wall, said rear wall being substantially flat and having a thickness of said blank and having a double thickness of said blank only where said opposing edges are joined in an overlapping relation, said walls being joined at one end of the bag to define a portion having a narrow cross-section said front and rear walls diverging from each other in a direction away from said one end when the bag is expanded to define a substantially triangular cross-section at a longitudinal plane disposed normal to said front and rear walls; a top wall of substantially the same width as said rear wall connected to said front, rear and side walls at the other end of the bag, fold lines being provided in said rear and side walls to permit movement of the bag from a collapsed condition to an expanded condition and said top wall extending from a vertical to horizontal position, said rear wall being folded back upon itself in said collapsed condition with a portion of said rear wall being adjacent to said top wall and facing in a common direction with said top wall which is opposite to a direction in which said front wall faces, said top wall being substantially normally to the longitudinal length direction of the bag in said expanded condition, an upper fold line being provided between said top and front walls to permit angular movement of said top wall relative to said front wall when the bag moves from said collapsed condition to said expanded condition, and access means provided in said front wall adjacent to said upper fold line and directly in front of an inner surface portion of said top wall when in said collapsed condition for providing access to an interior of the bag to permit air directed through said access means to impinge on said inner surface portion of said top wall and urge unfolding of said rear wall as said top wall angularly moves relative to said front wall together with separation between said front and rear walls to move the bag to said expanded condition suitable for receiving waste material,

2. A vacuum cleaner filter bag as defined in claim 1, wherein said access means comprises a flap punched out in said front wall; and apertured securing means disposed coextensively with said flap for securing the bag to a vacuum cleaner.

3. A vacuum cleaner filter bag as defined in claim 2, wherein said securing means comprises an apertured mounting collar mounted on said front wall to bring the aperture thereof in registry with said flap; and a resilient sheet of material mounted on said mounting collar and having an aperture provided in said mounting collar aligned with the latter, whereby passage of a vacuum cleaner element having the larger dimensions of the aperture in said mounting collar therethrough causes the element to be frictionally engaged by said resilient sheet to prevent inadvertent separation be tween the element and the bag during use. 

1. A VACUUM CLEANER FILTER BAG COMPRISING A BLANK SHEET OF AIR PERMEABLE MATERIAL DEFINING A FRONT WALL, A REAR WALL OF SUBSTANTIALY THE SAME WIDTH AS THE FRONT WALL AND A PAIR OF OPPOSING SIDE WALLS, OPPOSING EDGES OF SAID BLANK BEING SECURED TOGETHER IN AN OVERLAPPING RELATION TO DEFINE A TUBE-LIKE MEMBER, SAID OPPOSING EDGES OF SAID BLANK DEFINING COOPERATING PORTIONS OF SAID REAR WALL, SAID REAR WALL BEING SUBSTANTIAL FLAT AND HAVING A THICKNESS OF SAID BLANK AND HAVING A DOUBLE THICHNESS OF SAID BLANK ONLY WHERE SAID OPPOSING EDGES ARE JOINED IN AN OVERLAPPING RELATION, SAID WALLS BEING JOINED AT ON END OF THE BAG TO DEFINE A PORTION HAVING A NORROW CROSSSECTION SAID FRONT AND REAR WALLS DIVERGING FROM EACH OTHER IN A DIRECTION AWAY FROM SAID ONE END WHEN THE BAG IS EXPANDED TO DEFINE A SUBSTANTIALLY TRIANGULAR CROSS-SECTION AT A LONGITUDINAL PLANE DISPOSED NORMAL TO SAID FRONT AND REAR WALLS, A TOP WALL OF SUBSTANTIALLY THE SAME WIDTH AS SAID REAR WALL CONNECTED TO SAID FRONT, REAR AND SIDE AT THE OTHER END OF THE BAG, FOLD LINES BEING PROVIDED IN SAID REAR AND SIDE WALLS TO PERMIT MOVEMENT OF THE BAG FROM A COLLASPED CONDITION TO AN EXPANDED CONDITION AND SAID TOP WALL EXTENDING FROM A VERTICAL TO HORIZONTAL POSITION, SAID REAR WALL BEING FOLDED BACK UPON ITSELF IN SAID COLLAPSED CONDITION WITH A PORTION OF SAD REAR WALL BEING ADJACENT TO SAID TOP WALL AND FACING IN A COMMON DIRECTION WITH SAID TOP WALL WHICH IS OPPOSITE TO A DIRECTION IN WHICH SAID FRONT WALL FACES, SAID TOP WALL BEING SUBSTANTIALLY NORMALLY TO THE LONGITUDINAL LENGTH DIRECTION OF THE BAG IN SAID EXPANDED CONDITION, AN UPPER FOLD LINE BEING PROVIDED BETWEEN SAID TOP AND FRONT WALLS TO PERMIT ANGULAR MOVEMENT OF SAID TOP WALL RELATIVE TO SAID FRONT WALL WHEN THE BAG MOVES FROM SAID COLLAPSED CONDITION TO SAID EXPANDED CONDITION, AND ACCESS MEANS PROVIDED IN SAID FRONT WALL ADJACENT TO SAID UPPER FOLD LINE AND DIRECTLY IN FRONT OF AN INNER SURFACE PORTION OF SAID TOP WALL WHEN IN SAID COLLAPSED CONDITION FOR PROVIDING ACCESS TO AN INTERIOR OF THE BAG TO PERMIT AIR DIRECTED THROUGH SAID ACCESS MEANS TO IMPINGE ON SAID INNER SURFACE PORTION OF SAID TOP WALL AND URGE UNFOLDING OF SAID REAR WALL AS SAID TOP WALL ANGULARLY MOVES RELATIVE TO SAID FRONT WALL TOGETHER WITH SEPARATION BETWEEN SAID FRONT AND REAR WALLS TO MOVE THE BAG TO SAID EXPANDED CONDITION SUITABLE FOR RECEIVING WASTE MATERIAL.
 2. A vacuum cleaner filter bag as defined in claim 1, wherein said access means comprises a flap punched out in said front wall; and apertured securing means disposed coextensively with said flap for securing the bag to a vacuum cleaner.
 3. A vacuum cleaner filter bag as defined in claim 2, wherein said securing means comprises an apertured mounting collar mounted on said front wall to bring the aperture thereof in registry with said flap; and a resilient sheet of material mounted on said mounting collar and having an aperture provided in said mounting collar aligned with the latter, whereby passage of a vacuum cleaner element having the larger dimensions of the aperture in said mounting collar therethrough causes the element to be frictionally engaged by said resilient sheet to prevent inadvertent separation between the element and the bag during use. 